package com.pap.base.util.bean;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Required;

import com.google.common.collect.Lists;

public class BeanUtilss {

	/**
	 * 检查bean里标记为@Required的field是否为空，为空则抛异常
	 *
	 * @param bean
	 *            要检查的bean对象
	 */
	public static void checkRequiredFields(Object bean) throws Exception {
		List<String> requiredFields = Lists.newArrayList();

		List<Field> fields = new ArrayList<>(Arrays.asList(bean.getClass().getDeclaredFields()));
		fields.addAll(Arrays.asList(bean.getClass().getSuperclass().getDeclaredFields()));
		for (Field field : fields) {
			try {
				boolean isAccessible = field.isAccessible();
				field.setAccessible(true);
				if (field.isAnnotationPresent(Required.class)) {
					// 两种情况，一种是值为null，
					// 另外一种情况是类型为字符串，但是字符串内容为空的，都认为是没有提供值
					boolean isRequiredMissing = field.get(bean) == null
							|| (field.get(bean) instanceof String && StringUtils.isBlank(field.get(bean).toString()));
					if (isRequiredMissing) {
						requiredFields.add(field.getName());
					}
				}
				field.setAccessible(isAccessible);
			} catch (SecurityException | IllegalArgumentException | IllegalAccessException e) {
				// TODO LOGGER
			}
		}

		if (!requiredFields.isEmpty()) {
			String msg = "必填字段 " + requiredFields + " 必须提供值";
			// TODO LOGGER
			throw new Exception(msg);
		}
	}

}
